Can a heat pump work with existing radiators?

Why does water temperature matter?

A radiator gives off less heat with cooler water. Its output in an old quotation therefore cannot simply be reused for a heat-pump design. Ask for output at the intended flow and return temperatures.

Source: Daikin — warmtepompen en radiatoren

How do you check whether your radiators are suitable?

A trial with a lower central-heating flow temperature during cold weather can provide useful information. Ask an installer to adjust settings if needed; do not casually change domestic hot-water temperatures. A trial does not replace a calculation.

• Record each radiator’s dimensions and type, and identify rooms that stay cold.
• Have heat loss calculated for the home and individual rooms.
• Compare the required heat with manufacturer output data at the proposed water temperatures.
• Have pipework, water flow and controls checked too.

Must every radiator be replaced?

Not automatically. Only the living room may be critical, or insulation improvements may reduce demand. Compare keeping the radiators, upgrading selected radiators and using suitable low-temperature convectors.

Ask for emitter upgrades to be itemised separately. This distinguishes the heat pump’s price from the work needed to keep the home comfortable.

Is hybrid easier with existing radiators?

In a hybrid system the boiler can assist when needed. A suitable design still matters. An all-electric system must also deliver the required heat during cold weather.

Source: Milieu Centraal — hybride warmtepomp